#!/usr/bin/python
# -*- coding: utf-8 -*-

import sys, re, codecs, heapq, os
import numpy as np

from optparse import OptionParser

parser = OptionParser()
parser.add_option("-f", "--file", dest="corpus_file_path",
                  help="corpus file, one sentence per line", metavar="FILE")
parser.add_option("-n", "--name", dest="corpus_name",
                  help="name of the corpus")                  
parser.add_option("-l", "--n-most-frequent", type="int", dest="n_most_frequent", default=10, metavar="N",
                  help="output N most frequent sentences")                  
parser.add_option("-o", "--output-folder", dest="output_folder", default=".", metavar="PATH",
                  help="folder for storing _stats.txt file")                  

(options, args) = parser.parse_args()

html_pattern = r'<\/?(a|abbr|acronym|address|applet|area|b|base|basefont|bdo|big|blockquote|body|br|button|caption|center|cite|code|col|colgroup|dd|del|dir|div|dfn|dl|dt|em|fieldset|font|form|frame|frameset|h1|h2|h3|h4|h5|h6|head|hr|html|i|iframe|img|input|ins|isindex|kbd|label|legend|li|link|map|menu|meta|noframes|noscript|object|ol|optgroup|option|p|param|pre|q|s|samp|script|select|small|span|strike|strong|style|sub|sup|table|tbody|td|textarea|tfoot|th|thead|title|tr|tt|u|ul|var|xmp).*?>'
date_pattern = r'[0-9]{1,2}[\.\-/][0-9]{1,2}[\.\-/][0-9]{4}'
email_pattern = r'[\w\._\d]+@\w+(\.\w+)*'
number_pattern = r'[0-9]+([\.\,][0-9]+)?'


corpus_file = codecs.open(options.corpus_file_path, encoding='utf-8')

sentences = []
total_sentences = 0
empty_sentences = 0

print "Reading and hashing corpus file..."
for line in corpus_file:
    total_sentences += 1
    line = re.sub(html_pattern, '', line, re.UNICODE)

    line = re.sub(date_pattern, '[DATE]', line, re.UNICODE)
    line = re.sub(email_pattern, '[EMAIL]', line, re.UNICODE)
    line = re.sub(number_pattern, '[NUMBER]', line, re.UNICODE)

    words = re.findall(r'\[[A-Z]+\]|\w+', line, re.UNICODE)
    if any(re.match(r'\w+', word, re.UNICODE) for word in words):
        sentences.append(" ".join([word.lower() for word in words]))
    else:
        empty_sentences += 1
        
    if total_sentences % 10000 == 0:
        print "    processed %d sentences" % total_sentences
        

corpus_file.close()
print "Corpus file read."


print "Sorting the corpus"
sentences.sort()

print "Computing unique values..."

prev_sentence = None
curr_count = 1

ul = []

for i,sentence in enumerate(sentences):
    if sentence == prev_sentence:
        curr_count += 1
    else:
        if prev_sentence is not None:
            ul.append((prev_sentence, curr_count))
            curr_count = 1
    prev_sentence = sentence            

#append the last sentence
ul.append((prev_sentence, curr_count))

#print ul
print "Unique values computed."


print "Total sentences %d, empty: %d" % (total_sentences, empty_sentences)
print "Among %d non-empty sentences there are %d unique sentences" % (total_sentences - empty_sentences, len(ul))
print "%d most common sentences:" % options.n_most_frequent


sep = '@#@'

with open(options.output_folder+'/'+os.path.basename(options.corpus_file_path)[:-4]+'_stats.txt', 'wb') as output_file:
    
    
    corpus_name = options.corpus_name if options.corpus_name is not None else options.corpus_file_path[:-4]
    output_file.write(corpus_name+sep+str(total_sentences)+sep+str(empty_sentences)+sep+str(len(ul))+'\n')

    for sentence, count in heapq.nlargest(options.n_most_frequent, ul, key = lambda x:x[1]):
        print "%d occurences of sentence: %s" % (count, sentence)
        output_file.write(str(count)+sep+sentence.encode('UTF-8')+'\n')